Arati Prabhakar, the director of the Defense Advanced Research Projects Agency, or DARPA, briefs Defense Secretary Chuck Hagel on the Atlas robot and other robotics at the Pentagon, April 22, 2014. Arati Prabhakar, the director of the Defense Advanced Research Projects Agency, or DARPA, briefs Defense Secretary Chuck Hagel on the Atlas robot and other robotics at the Pentagon, April 22, 2014. SHARE IMAGE: Download Image: Full Size (0.42 MB) Tags: Photo Essays Photo By: VIRIN: 275193-V-ACR90-586.jpg Photo Gallery